on my mum's old bernina (same age as me), my dad rigged up a regular plastic coathanger which he attached with a large rubber band - works super well
sorry can't find the picture right now
oh - and to keep the spool from going off doing its own thing, i just stand it inside a large glass, beermug, high bowl - something a bit wider than the spool - tall enough to keep it in place and heavy enough so it stays put.